I do not intend here to define the ultimate meaning of intelligence but rather a starting point from which to provide an operational, useful, way to use the term. No one has yet provided a complete description, yet alone all the types of intelligences that exist. The psychologist, Howard Gardner, for example, identified up to 9 different types of intelligences that exist in the human alone. Indeed, there may occur types of intelligences that we have no way (as yet) to determine. It might prove ultimately impossible to pin down the meaning of intelligence simply because, at some level, intelligence requires creativity which, if attempted to define, contradicts the very notion of creativity! Perhaps like pornography, we know it when we see it. I will therefore stick with a very basic meaning of intelligence.

The dictionary meaning defines intelligence
as "the capacity to acquire and apply knowledge by means
of thought and reason." Note, this meaning leaves out many
other capabilities which we might also consider intelligent. For
example an artist who creates an abstract painting does not necessarily
need to acquire knowledge nor even apply it through reason, yet
we label many artists as intelligent or genius. [1] However at
least one common denominator seems requisite for all known types of intelligences
to occur: thinking. To have intelligence means having the
ability to think. All forms of thinking (excluding, perhaps extremely
insane forms of thinking) results in some kind of intelligent
action, even if it may seem very low intelligence to us. The neurological
understanding of the mechanisms of intelligence remains unclear
but I suspect that we will discover that the terms "intelligence"
and "thinking" will prove entirely synonymous.

Usually intelligent actions aim to solve a problem for a
goal or to fulfill a desire but what has the capacity to acquire knowledge?
Most people assume that only humans and supernatural entities have intelligence,
but does intelligence require biological or superstitious agencies at all? I
submit that most people confuse intelligence with consciousness or awareness,
yet the operational meaning of intelligence doesn't require consciousness at
all.

A key to understanding intelligence requires
the understanding of its basic mechanism for obtaining it: thinking.
Again, most people confuse thinking with consciousness and awareness,
probably due to the fact that most people believe that only humans
(and gods) have the capacity to think. But do only humans think?
I submit that anything with a brain, thinks. Natural selection
evolved brains because brains allow an organism to gather knowledge
about the outside world and to utilize it to help them survive.
In spite of past philosophers attempts to put humans on the pedestal
of life and to declare that only humans think, research into brain
biology over the past 30 years has shown that even a lowly worm
has the capacity to think and reason at some basic level. And
because nervous systems developed into simple brains and simple
brains evolved into complex brains, so did the capacity to think
and acquire knowledge. And since intelligence comes from mechanisms
that think, so also does intelligence evolve-- along with the
brains that hold intelligence.

The very task of acquiring knowledge predisposes
an initial ignorance before obtaining and applying knowledge.
This means that any intelligent entity must also possess limitations
and unknowns about the universe before it can gather information
and knowledge. Nowhere does intelligence require consciousness,
or self-awareness in order to achieve the capacity to acquire
knowledge and apply it (although it could certainly enhance it).

Ever since natural selection evolved us,
a new kind of brain capable of simple thinking emerged through
our inventions-- computers. Unconscious computers, for example,
can meet all the requirements for simple intelligence. Computers
can think (calculate) by performing logical rules within algorithms,
gather information (knowledge) about its environment though sensors,
and apply its acquired knowledge for an unconscious goal. To achieve a goal means to gather information
about the environment (knowledge) and to make predictions from
that information.

Alan Turing and especially, Hilary Putman, first proposed the computational theory of mind that linked human thinking to a form of computing. Thinking
then, means a dynamic system able to manipulate abstract symbols,
regardless of whether they occur in nervous systems, brains, computer
programs, or neural nets.
To gather information requires senses, or sensors and the ability
to attach labels to the sensed perceptions and to manipulate these
labels to make predictions (algorithms, thinking). Biological
intelligence evolves out of multi-cellular bodies with senses,
nervous systems or brains (wet-ware). Non-biological forms of
intelligence require sensors, electrical networks or computer
brains (hardware).

From everything we know about intelligence,
one thing remains clear: intelligence requires some kind of central
processing system-- a brain. Whether the brain consists of biological
or electrical components, it must have the capacity to acquire
and apply knowledge by means of thought and reason.

Where we find intelligence

The only kind of intelligence that we know
of comes in two forms: non-conscious and conscious. These forms
occur in either of two types of physical vessels: biological life-forms
and mechanical-electrical devices invented by humans. They actually
exist, and both types occupy a limited space in the universe on
a tiny planet called Earth. We know of no other forms of intelligence.
We have not a shred of evidence that intelligence (as we know
it) exists elsewhere in the universe, beyond it, or in a supernatural
world.

2. Animals foraging for food. (conscious,
but some philosophers still debate this)

3. Apes climbing a tree. (some self-consciousness)

4. Humans inventing a machine. (self-conscious)

5. Robots performing mundane tasks (unconscious)

6. Computer algorithms solving a navigational
problems (unconscious)

7. A chess program beating the world's best
grandmaster (unconscious)

All of the above examples require some form
of brain with the capability to think.

Note the progression of biological intelligence
always stem from non-conscious intelligence to conscious
intelligence (evolution), never the other way around (creationism).
The arrow of time (entropy) puts non-conscious intelligence always
before conscious intelligence on the past-future time scale. Millions
of years ago, only simple celled life-forms existed, then came
multi-celled life, then multi-celled life with simple brains,
and then more complex brains, and finally brains with self-awareness
and consciousness-- dolphins and apes (humans get classified within
the ape family). All of these biological life-forms contain recipes
of DNA, the mechanism of replication which carries with it intelligent
expressions (phenotypes).

In the last few thousand years, a new replicant
evolved out of biological life- memes. Memes propagate similar
to genes but they can pollinate through brains in animals that
have social cultures. Humans happen to have the most developed
meme transfer methods as they have invented ways to store information
in books, tapes, computer disks, CDs, and have even invented machines
to manipulate them in dynamic ways. These man-made dynamic manipulations
has resulted in a new media for intelligent evolution. Instead
of biological intelligence transferred through DNA made brains,
we now have begun to see the evolution of mechanical-electrical
intelligence. Like biological evolution, mechanical-electrical
intelligence also began from non-conscious means. It remains for
us to see whether these meme-machines will develop consciousness
and self-awareness.

Although the four forms of intelligence
above appear to describe discrete categories, the actual evolution
from non-conscious to consciousness does not occur within aristotelian
dichotomies, but rather through a continuum. You might ask yourself
at what level of evolution does consciousness exist in animals.
We have little problem with seeing evidence of consciousness in
humans, apes, dolphins, or even cats and dogs, but what about
insects, microbes and viruses? Trying to pigeonhole just where
non-con consciousness ends and consciousness begins only misses
the mark and can lead us to create reification fallacies.

Even though describing categories of intelligence
in general terms helps us understand the broad ranges, viewing
the evolution though a time continuum gives us a more accurate
way to understand its development.

One might also ask what consciousness has
to do with intelligence. Since we know that computers have intelligence
and no consciousness, why should we even classify intelligence
with consciousness at all? Consciousness has more to do with feelings
and emotions (qualia) than it does with intelligence. In fact
you can even train yourself to eliminate thought (and thus no intelligence)
through mediation or biofeedback techniques, at least briefly,
but you will still feel. It appears that consciousness
evolved later in complex brains, perhaps even as an emerged property
of brain chemistry.

As to the problem of defining artistic intelligence,
it may simply come in the form of attaching thinking with feeling.
Instead of obtaining knowledge about the outside world, the artist
(at least on some level) relies on inner feelings. Artists use
their inner feelings and emotions in combination with thought
and action (craft) in order to express their emotions and feelings.
Painting, dancing, acting, or whatever artistic media you choose,
you must do it through qualia (feelings, emotions), thought (where
to place your brush, color, or movement), and apply it in some
media format.

The God meaning of intelligence

Interestingly, the people who speak most
about godly intelligence fail to give an operational meaning for
intelligence. In its most common expressed form, a religious believer
will define god's intelligence as possessing supreme knowledge
(omniscient). The shift from Creationism to Intelligent Design
theory gives, perhaps the most evasive and yet empty example for
the meaning for intelligence. In spite of the long held belief
that a monolithic entity possess an extreme form of intelligence,
we never hear a good argument to exactly what the term intelligence
means. It does no good to define intelligence as omniscience because
this term only describes the end result of intelligence,
not intelligence itself. Moreover we have no way to test for omniscience.

Revealingly, nowhere in the Bible does it
use the term "intelligent" in reference to God. In fact,
nowhere in the KJV Bible does it even use the word except in one
verse (Daniel 11:30) where it uses "intelligence" in
reference to information about an enemy.

We know about intelligence because we observe
it in ourselves and in others. Many times people project this
idea to inanimate objects and fictions that they want or need
to believe in (religions). I suspect that most religious people
confuse intelligence for what they think of as a conscious entity
(an entity that has feelings coupled with awareness). A personal
god. Surely Christians believe that their god possess a super-consciousness,
an entity that has awareness of everything in the universe, a
grand peep-master that sees and judges everything people do. And
it comes from this super-consciousness that they also believe,
incorporates intelligence. In other words, they believe that one
cannot exist without the other: to have intelligence means to
have consciousness and to have consciousness means having intelligence.
In spite of this fantasy, our only model for intelligence comes
from our own limited intelligence. And since believers always
think of their gods as supreme or unlimited (but how would they
know?), they naturally assign extreme intelligence-consciousness
to their object of worship. But notice that nothing above provides
a meaning for intelligence itself (it consists entirely
as circular reasoning).

If a god does possess intelligence then
it cannot exist as omniscient because intelligent beings must
possess uncertainty in order to acquire knowledge (If you know
everything, then you can't acquire knowledge because you
already have all of it). And if an entity knew everything, then
it would have nothing to do!

Clearly intelligence does not require consciousness,
nor does it require feelings or emotions, and yet religionists
hold this very idea as somehow important to their theology. I
submit that they haven't a clue as to what they mean, and this,
perhaps, explains in part why religion has never had the capacity
to explain any of the world's phenomena. Religion has everything
to do with self-consciousness, not intelligence, and self-consciousness
without intelligence produces the very delusions derived from
their beliefs.

Notes:

[1] Those who have read Alfred Korzybski's
view of over-under defined terms might see the limiting factor
of the word intelligence here. A label can never include all and
varying differences of objects, properties and their reactions.